The present invention relates to a method of optimizing target coverage for a computer-controlled automatic gun anti-aircraft defense weapon equipped with proximity fuze activated explosive shells.
The capability of modern anti-aircraft defense systems to combat difficult air targets such as aircraft and missiles has indeed been increased through the availability of high-class reconnaissance and fire control radar, laser rangefinders and rapid computers combined with quick-firing fully automatic anti-aircraft guns equipped with proximity fuzed shells. However, at the same time, the targets have become more difficult to combat, and completely new and extremely difficult to combat types of targets such as the so-called seaskimmers and cruise missiles have appeared on the scene. A common feature of most modern anti-aircraft target types, regardless of whether they consist of aircraft, helicopters or missiles, is also that they operate tactically in such a manner that the anti-aircraft defence weapon has very little time for target detection, target range measurement, calculations, gun aiming and firing. It is therefore essential for the anti-aircraft gun to rapidly engage and to cover the target with effective fire. Despite the available material, ever greater technical requirements and consequent higher competence, the risk nevertheless always remains that minor errors in target range measurement and calculations and unpredictable manoeuvres by the targets such as tactically unjustified changes in course and rapid changes in speed and/or atmospheric fluctuations can result in misfires. The greatest chance of effect in the target is therefore obtained if one directly covers the point and area around which it is calculated that the target will be when the projectiles reach their destination with several shells whose coverage range has its focal point in the previously mentioned point where the target is calculated to be. A certain well-defined dispersion of the various shells in one and the same round is therefore desirable. Although it is true that each weapon gives rise to a certain dispersion between the hit points for several succeeding shells experience has nevertheless shown that this dispersion is too limited to give the desired result when it comes to combating contemporary air targets. Naturally it is also undesirable to reduce the accuracy of the anti-aircraft guns because this would reduce possibilities of actually hitting the point where the target is estimated to be at a specific point of time.
It has previously been proposed that a specific pattern of hits around the estimated position of the target shall be forced about through minor angular corrections for the gun between the individual shells in a round. This can take place, for example, by moving the gun around the point of aim during firing. This method was often practiced, for example, with older types of manually laid machine gun and light automatic gun anti-aircraft defense with simple laying means. Naturally the method can also be used for a predetermined automatic displacement of an anti-aircraft gun during firing. The same result can also be achieved by building in some displacement into the gun between the hit points of the individual shells and the calculated aiming point of the gun. This method has been tested, for instance, on today's multi-barrel gatling guns. These guns are equipped with a plurality of barrels which are rotated around a shaft disposed in the firing direction of the gun, and the different barrels are fired consecutively upon reaching a specific firing position while the other part of the revolution around the shaft is exploited to remove the empty cartridge cases and to reload the different barrels. In these gatling guns, the desired dispersion has been achieved by setting certain barrels at a slant relative to the shaft of the gun.
Both the latter method according to which the different barrels fire around the aiming point in accordance with a certain schedule and the previously mentioned method according to which the gun moves in accordance with a predetermined program during firing give rise, however, to purely angle-dependent hit patterns where the dispersion between the individual shells is completely dependent on the distance to the target. With these methods, then, the optimized hit pattern can only be achieved at a single normal firing range.